This project focuses on basic and applied research on human retroviruses, HIV-1 and HTLV-I. It covers three broad areas: I) basic research studying the regulated expression of HIV-1; II) basic research on cellular transformation events as related to HTLV-I; and III) applied research towards developing HIV-1-based vectors and designing molecular ribozymes targeted against HIV-1.Some notable scientific findings from our research program in 1998-1999 include: 1) the cloning of the human IKK-gamma cDNA; 2) the identification of epithelins as extracellular Tat co-factors; 3) the generation of attenuated HIV-1 molecular clones using IkB-alpha protein; 4) the elucidation of redox regulation of selenoproteins as a consequence of HIV-1 infection of T- cells; 5) the characterization of a novel Tax-binding protein that has an anti-apoptotic phenotype. - AIDS, Adult T-cell leukemia, Cancer, HIV-1, HTLV-I